Hectograph blanket



Patentecl Sept. 2, 1947 HECTOGRAPH BLANKET Irwin Kramsky, Chicago, andMelville J. Holik, Berwyn, Ill., assignors to Ditto, Incorporated,Chicago, 111., a corporation of West Virginia No Drawing. ApplicationOctober 31, 1945, Serial No. 625,952

6 Claims; (01. 117-355) 1 The invention relates to composite bondedsheet material and more particularly to hectograph blankets and tomethods of preparing the same. Hectograph blankets generally comprise agelatinous copy mass secured to a flexible backing,

In one type of hectograph blanket in commercial use the backing has beensecured to the copy mass by means of an intermediate layer of drying oilsuch as linseed oil. The drying oil may be used by itself or in alacquer composition. In one type of blanket the backing is coated with adrying oil and then the side remote from the copy mass is coated with alacquer such as a cellulose ester lacquer which serves as a protectivecoating. The success of the bond These compounds may be incorporatedwith all types of gelatin containing compositions for which it isdesired to obtain an eflicient bond to a backing of paper, cloth, metalor the like, particu larly where the backing is coated with acompositionconsisting of or containing a drying oil such as linseed oil,poppy oil, tung oil and the like. However, our invention is particularlyapplicable to secure hectograph compositions to paper or cloth backings.These hectograph compositions, as is well known in the art, are gelatinbetween the copy mass and the drying oil coated backing has been subjectto a variety of factors contingent upon (1) degree of oxidation of thedrying oils (ageing); (2) humidity and temperature conditions; and (3)quality and concentration of the gelatin and glue used in the copy mass.

Anobject of this invention is to provide an improved bond between thehectograph copying mass and the intermediate layer containing a dryingoil. A further object is to provide a method for bonding of a gelatinlayer t a backing, which method is not so dependent upon degree ofoxidation, humidity and temperature and quality and concentration ofgelatin as is present with meth ods hitherto used employing drying oilsas bonding agents.

Other objects and advantages of the invention will become apparent asthe following detailed description progresses.

We have found a series of compounds which,

when added to a gelatin composition such as a hectograph copy mass,facilitate the adherence of the copy mass to a drying oil coatedbackingand otherwise accomplish the objects of our invention. Thesecompounds consist of water soluble hydroxy aliphatic monoamines andwater soluble oxygen containing heterocyclic amines which containnitrogen in the trivalent form. Suitable compounds include, for example:

(a) Z-amino-l-butanol (b) Mono, di, and triethanolamine (0) Mixedisopropanol amines (d) Tris (hydroxymethyl) amino methane (e) 2-amino,2-ethyl, 1,3-propanediol (f) 2-amino, Z-methyl, 1,3-propanediol (g)Z-amino, 2-methyl, l-propanol (h) Diethylaminoethanol (i) Morpholine(7') Ethyl morpholine gels containing a major proportion of a relativelynon-volatile water soluble material such as glycerin. For example,hectograph blankets generally contain to 1 part by weight of gelatin, 5to 20 parts by weight of glycerin, and from 1 to 3 parts by weight ofwater. The water soluble amine may be incorporated in this compositionin a proportion of 1% to 50% by weight, preferably from 5% to 25% byweight. Minor proportions of tanning agents based on the gelatin arealso incorporated in the mixture. Formaldehyde, aluminum alums, chromealums and potassium and ammonium dichromates may be used. For example,.001 to .01 of potassium dichromate may be incorporated in thegelatinous mass.

To more clearly set forth the practice in accordance with the invention,and to more specifically point out the nature of the product and processcontemplated thereby, several specific, illustrative examples ofsuitable compositions are hereinafter set forth, it being understoodthat these examples illustrate several embodiments which have givensatisfactory results and are not intended to restrict the inventionthereto.

Example I Parts 225-bloom gelatin 150 Water 200 2-amino, 2-methyl,1,3-propanediol 15 Glycerin 1800 Q Example II Parts 225 bloom gelatin150 Water 200 Triethanolamine 25 Glycerin 1790 Example III Parts 225bloom gelatin 150 Water 200 Aminobutanol 25 Glycerin 1790 To prepare thegelatin I compositions, the gelatin was first soaked in the aqueousamine solution, then warmed to 53 C. and added to the glycerin, whichhas been preheated to 62 0.

While we do not intend to be limited to any theory as to the action ofamine compounds, the following explanation is given for the purpose ofaiding and'understanding "our invention:

Assuming a structure for the unsaturated, free fatty acids of the dryingoils in the bonding layer to be upon oxidation, a diperoxide' structurere iree sented by the formula:

R-CH-OH- -1 3HoH-- eco-n where 0 represents nitrogen electrons andrepresents R electronsitmay be shown that, being soluble in water, 7

a h drated: amine of' the oxonium type" based upon a coordinatelinkmvoiving a-covalent' hydrogen; called the hydrogen bond, a semipolar linkage; This linkage is semi-ionic in nature, and its resence isestablished from the number of covalent bonds in th'e c'omp'letedvalence-shell of the atom; Onje'of the valencesorpentavalent nitrogen isan electrovalence different from the other four; The four covalences ofnitrogen have a tetrahedral spatialarrangement; but thegroup held" bythe electrovaience is attracted by the ammonium ion' as aunit by virtueof" the" eiec trostaticcharge without definition" of direction; Thiscompound; then; is" capable or forminga substantially stable saltattributable to the res onance effect allied with; hydrogen bond.

This is believed to react with the peroxide por tion of the-oxidizedunsaturated free fatty-acid asfollows: the-amine hydrate-forms an amineoxide hydrate from theperoxide',

' iflar=oxygenelectrons i. .7, this hydrate then forms a partial etherlinkage with the ethylenic oxide,

4 Thus the conversion of trivalent nitrogen makes it possible to form aconnecting bridge with the bonding layer. This is substantiated by thefact that pentavalent nitrogen compounds do not perform this function.

Since protein, e. g., gelatin org'luais a hydrophilic colloid, and thecase of a; colloidal solution of a more or less linear molecule of highmolecular weight, such as gelatin is assumed to be, produces aninterlocking network of molecular fibers leaving a high proportion ofopen liquidfilled spaces which'retain their properties of electricalconductivity and difiusivity of solute, it can'logicallybe assumed thatgroups of a hydrophilic character, such as hydroxyl, will seek out theinterstices of water and become imbedded in the colloidal solution. Thusa bridge linking the bonding layer to the protein layer is establishedbetween the amine portion of a molecule, andthehydroxyportion ofamolecule.

While we have described certain preferred em bodiment-s of ourinvention, many modifications thereof may be made without departing fromthespirit of the invention; and we do not wish to belimited to t-hedetailed examples, formulas, and proportions of ingredients herein setforth, but desire to avail-ourselves of allchanges within the scope ofthe appended claims,

We claim:

LA composite sheet comprising a layer of gelatin containing a: compoundselectedfrom the group consisting of water soluble hydroxy all-'- phaticmonoamines and water soluble-oxygen con-- taining heterocyclicmonoamines containin nitrogen in a trivalent form; abacking, and anintermediate layer containing a drying oil.

2-. A heotograph blanket comprising a backing, a gelatinous copy masscomprising gelatin and containing a compound selected from the groupconsisting of water soluble hydroxyaliphatic monoamines and watersoluble morpholines; and an'intermediat'e-bonding layer comprising adrying oil;

3. A hectograph blanket comprising a fibrous backing-,a gelatinous copymass comprising gelatin and containing a' compound selected fromthegroup consisting of water soluble hydroxy aliphatic monoamines andwater soluble morpho'lines; and an intermediate bonding layer of linseedoil. 7 H i 4. A hectograph blanket comprising abacking, a gelatinouscopy mass comprising gelatinand containin a hydroxyaliphaticmonoamine;and an intermediate bonding layer comprising: a dryingoil. 4

5'; A hectograph blanket comprising a backing, a. gelatinous copy. masscomprising. gelatin and containing. an ethanolamine, and an intermediatebonding layer comprising a drying oil.

6'. A liectograph blanket comprising a backing, a elatinous copy masscomprising gelatin and containingja morpholine'; a backing, and anintermediatelayercontaining a drying Oil.

IRWIN KRAMSKY.

REFERENCES CITED The following references are oirecordin" the file ofthis patent:

UNIT EDSI'ATES -PATEN 'ISf Number Name Date V 1,982,018 OwenNovr27,:1934

